Adjustment assembly for a harvesting machine

ABSTRACT

An arrangement for the automatic adjustment of the cut height of a front harvesting attachment on a harvesting machine for the harvesting of stalk-like plants. A controller is connected to a sensor and to an actuator that can adjust the cut height of the front harvesting attachment based on the detection by the sensor of at least one characteristic of the harvested crop material and can be repositioned as a function of the signal of the sensor.

BACKGROUND

1. Field of the Invention

The invention concerns an arrangement for the automatic adjustment ofthe height of cut of a front harvesting attachment on a harvestingmachine for the harvest of stalk-like plants.

2. Related Technology

Forage harvesters are used primarily for the harvest of grass, corn orother forage plants. While pick-ups that are guided at a constant heightabove the ground by touch contact are used in harvesting of grass, theuse of corn heads or cutter heads is common practice as the frontharvesting attachment for forage harvesters in the harvesting of corn orthe whole plant silage of cereal crops. The height of cut of such frontharvesting attachments for the cutting of stalk-like crops can bevaried.

In the state of the art, the height of cut is provided as an input bythe operator of the forage harvester and is controlled automatically bythe control arrangement with the use of sensors and actuators. In such away, a predetermined height of cut or a predetermined contact pressureof the front harvesting attachment is maintained. In the case of theinput of the height of cut contradictory interests must be considered.On the one hand, the cut height of the front attachment of a forageharvester has a considerable effect upon the yield per unit area and thelength of the remaining stubble on the field. On the other hand, it alsoaffects the quality of the mass of forage produced where a low cutheight is less desirable in the light of the optimization of thequality. Ground particles, such as sand particles, adhering to stalks(for example, stalks of corn plants) can considerably increase the wearof cutting tools on front harvesting attachments and of followingmachine components such as chopper arrangements. Due to costconsiderations, it may not be in the interests of the operators of suchforage harvesters to utilize the lowest cut height. On the other hand,plowless farming (in connection with direct sowing) is gainingconsiderable significance. This, in turn, demands the least possiblelength of stubble and, hence, the lowest cut height. Thus, the operatorof the forage harvester is confronted by the problem of finding theoptimum cut height associated with the immediate case.

Moreover, the harvest of high energy silage, that is, corn with a highproportion of corn cobs, the harvested crop must be cut at a relativelygreat height above the ground. Here, the operator must see to it thatthe plants are cut as close as possible underneath the corn cobsthemselves. A manual re-adjustment of the cut height does not, as arule, lead to optimum results over large time intervals.

DE 102 25 098 A proposes that the cut height used in each case bedetected by measurement technology and to log the cut height with ageographical reference. This, however, does not assist the operator inthe selection of the appropriate cut height.

It has also been proposed that various properties particularly thenitrogen and protein content of a cereal crop be analyzed by means of anappropriate sensor during the harvest of the cereal crop with a combine.As a result of the analysis, the cereal crop is loaded into differingcontainers. EP 0 732 740 A, WO 03/029792 A and “Protein Mapping ofSpring Wheat using a Mobil Near Infrared Sensor and Terrain Modeling”,Corey Grant Meier, M. Sc. Thesis, Montana State University, Bozeman,Mont., USA, April 1004, all relate to this concept. Also, an analysis ofthe material contents on board a forage harvester is described in DE 19922 867 A. In this reference, the results of the analysis are merelymapped.

The problem underlying the invention is seen as the need to simplify foran operator of a forage harvester the adjustment of the cut height.

SUMMARY

The invention proposes that the cut height of the front harvestingattachment be controlled automatically as a function of a measuredcharacteristic of the plants being harvested. The characteristic isdetected by means of an appropriate sensor (for example, an opticalsensor that preferably operates in the near infrared region inreflection or transmission mode) arranged at any desired location in thematerial flow. The characteristic of the plants detected by the sensormay be an amount of a material contents of the plant such as thecontents of protein, nitrogen or energy or a magnitude previously storedin memory or of contaminants (for example, earth or sand). In the latterinstance, it becomes possible to reduce the amount of contaminants inthe harvested forage and thereby to increase the quality.Simultaneously, the work load on the operator is reduced and aninexperienced operator can deliver a good operating outcome.

Various strategies or target inputs may be programmed into thecontroller connected to the adjustment assembly, according to which itcontrols adjustment as a function of the signals of the sensor. One ormore value inputs may be provided as permanent input or may be selectedby the operator. One possible target value input could be to hold theproportion of contaminants in the forage to a minimum value. If thistarget value input is selected, the height of cut is raised untilcontaminants are limited to a defined threshold value (that is a levelof permanent input or an input that can be selected) or no contaminantsexist in the harvested plants. Another possible target value input couldbe a maximum proportion of fiber attained in the forage. In thisinstance the controller would lower the height of cut as far as possiblebased on the target value. In this case, a combination could be selectedfor the target value input with respect to the contaminants, that is,the height of cut is lowered until a defined limit value, or one thatcan be provided as input, is reached for the contaminants contained inthe forage. Another possible target value input could be the maximumenergy contents of the forage, where the energy contents can be providedas input by the operator or be pre-defined. Thereby certain qualities ofthe forager can be attained automatically. Other target value inputs canalso be combined in any manner desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become readilyapparent to persons skilled in the art after a review of the followingdetailed description of a preferred embodiment, with reference to theappended drawings, which shows:

FIG. 1 shows a schematic side view of a harvesting machine with anarrangement for the adjustment of the cut height of a front harvestingattachment; and

FIG. 2 shows a pattern for the adjustment of the height of cut of thefront harvesting attachment.

DETAILED DESCRIPTION

A harvesting machine 10, shown in FIG. 1 in the form of a self-propelledforage harvester, is supported by a frame 12 that is carried by drivenfront wheels 14 and steerable rear wheels 16. The harvesting machine 10is controlled from an operator's cab 18 from which a front harvestingattachment 10, appropriate for harvesting stalk-like plants, can becontrolled visually. In the shown embodiment, the front harvestingattachment 20 is a corn picker head operating independently of rows. Itconducts crop taken up from the ground (for example, corn, cereal cropor the like) to a chopper drum 22, by means of upper pre-pressing rolls30 and lower pre-pressing rolls 32, where it is chopped into smallpieces and delivered to a conveyor arrangement 24. The crop leaves theharvesting machine 10 to an accompanying trailer (not shown) over adischarge arrangement 26 whose position can be adjusted. A post-chopperreduction arrangement 28 is located between the chopper drum 22 and theconveyor arrangement 24, and through which the crop to be conveyed isconducted tangentially to the conveyor arrangement 24. The invention canalso be applied to other harvesting machines that process stalk-likecrops, for example corn balers.

The front harvesting attachment 20 and the intake housing 34 of theharvesting machine 10 that carries it, in which the pre-pressing rolls30 and 32 are also arranged, are supported in bearings free to pivotabout the axis of rotation of the chopper drum 22. The pivoting of thefront harvesting attachment 20 about this axis of rotation is performedby an actuator 36 in the form of a hydraulic cylinder. The pivoting ofthe front harvesting attachment 20 also provides for the adjustment ofthe cut height of the front harvesting attachment 20; that is, theheight at which it cuts off the plants from the stubble remaining in theground. The hydraulic cylinder is connected in joints at one end to theframe 12 and at the other end to the intake housing 34. Such an actuator36 may be provided on both sides of the intake housing 34.

The actuator 36 is single acting, or it may be double acting, and may beconnected, so as to carry hydraulic fluid to a pump 42 or a reservoir 44over a valve arrangement 40 (see FIG. 2). The valve arrangement 40 iscontrolled electromagnetically by a controller 38. The controller 38 andthe elements for repositioning the actuator 36 as described here areprovided as ongoing production components on harvesting machines. Afeedback sensor (not shown) can transmit a signal to the controller 38regarding the immediate position of the actuator 36 or the pivot angleor the intake housing 34 about the axis of rotation of the chopper drum22. The controller 38 is, in particular, the machine controller thatalso controls other functions of the harvesting machine.

The controller 38 is connected with a sensor 46 and an input and displayarrangement 48. The sensor 46 is arranged on the upper side of thedischarge arrangement 26. It operates in the near infrared region anddirects a broadband light on the chopped plants in the dischargearrangement 26 and resolves the light reflected by plants into spectraby means of wavelength dispersion elements (grating or the line). Thereflected spectra is detected by appropriate light sensitive detectorsdetected in specific wavelengths. An appropriate sensor is described byU.S. Pat. No. 6,421,990, whose contents is incorporated into the presentdocument by reference.

The sensor 46 detects several properties of the chopped plants,particularly their material contents or one more values derivedtherefrom. The material contents of particular interest are organicmaterial components, such as amylum, enzyme soluble organic substances(ElosT), oil and raw protein, and the proportions of these components inthe harvested crop. In additional, the contents of non-organiccomponents such as mineral components (ash), example, sodium andmagnesium, contaminants in the form of sand (silicon dioxide) and earth,water and the color of the plants can be measured.

Parameters of the harvested crop that are detected, in addition oralternatively to the material components, or that can be derivedtherefrom are the contents and the raw fiber contents of the harvestedcrop. The raw fiber contents and the fiber length can be determined, inparticular, by further processing of the output signals of the sensor 46by means of a program running in the controller 38.

The controller 38 has available, on the basis of the signals of thesensor 46, information and similar data regarding the protein contents,the energy content and the proportion of contaminants in the choppedplants. The operator in the operator's cab 18 can read the actualmagnitudes of these values at any time by means of the input and displayarrangement 48. The input and display arrangement 48 makes it possiblefor the operator to select the height of cut of the front harvestingattachment 20, on the basis of which target value the controller 38 isto adjust. In addition, this target value can be provided as input orselected from among several inputs. During the harvesting operation thecontroller 38 controls the actuator 36 on the basis of signals of thesensor 46 in such a way that the target value inputs are maintained.Thereby a certain energy content or protein content in the forage isattained or a predetermined degree of contamination is not exceeded. Byway of inputs into the input and display arrangement 48, the operatorcan vary the target values at any time and, if useful, manually overridethe outputs of the controller 38 in order to raise the front harvestingattachment 20 in time to avoid a collision with an obstacle, forexample. A conventional sensor for determining the height above theground of the front harvesting attachment and/or the contact pressure ofthe cutter head upon the ground may also be connected with controller38. The controller 38 utilizes the signals of this sensor in order toprevent the front harvesting attachment 20 from being lowered too far,positions in which, for example, it could penetrate the ground.

The measurement results of the sensor 46 and the cut height at the timeare geographically referenced and stored in memory by the controller 38for later evaluation, for example, for subsequent fertilization. In thisway the height of the stubble remaining on the field can be consideredas plant food input in a fertilizer calculation.

As a person skilled in the art will readily appreciate, the abovedescription is meant as an illustration of implementation of theprinciples this invention. This description is not intended to limit thescope or application of this invention in that the invention issusceptible to modification, variation and change, without departingfrom the spirit of this invention, as defined in the following claims.

1. A cut height adjustment assembly for a harvesting machine, theassembly comprising: a harvesting unit supported by the harvestingmachine and configured to cut stalk-like crop material at a height aboveground level; an actuator including a moveable portion being moveablebetween first and second positions, the actuator being connected betweenthe harvesting unit and the harvesting machine such that movement of themoveable portion between the first and second positions causes movementof the harvesting unit relative to the harvesting machine and adjuststhe height above ground at which the harvesting unit cuts crop material;a sensor configured to detect at least one characteristic of the cropmaterial after harvesting and transmit a signal based thereon; and acontroller coupled to the sensor and the actuator, the controllerconfigured to cause movement of the actuator and the harvesting unit inresponse to the signal from the sensor, whereby the cut height of theharvesting unit is adjusted.
 2. The assembly according to claim 1wherein the sensor is an optical sensor.
 3. The assembly according toclaim 2 wherein the sensor is a near infrared sensor.
 4. The assemblyaccording to claim 1 wherein the sensor is configured to detect acharacteristic of the crop material that is a material contents or amagnitude derived therefrom.
 5. The assembly according to claim 4wherein the material content is a protein content.
 6. The assemblyaccording to claim 4 wherein the material content is an energy content.7. The assembly according to claim 4 wherein the material content is acontaminant content.
 8. The assembly according to claim 1 wherein thecontroller is configured to receive at least one target value input forthe property on the basis of which the controller determines a targetvalue for the cut height.
 9. The assembly according to claim 8 whereinthe controller is configured to receive one or more target value inputsthat can be selected from a list of differing target value inputs. 10.The assembly according to claim 8 wherein the target value input can beselected as a proportion whose value is defined.
 11. The assemblyaccording to claim 8 wherein the target value input can be selected as aproportion whose value can be defined.
 12. The assembly according toclaim 1 wherein the sensor that interacts with the crop material thathas been harvested.
 13. The assembly according to claim 1 wherein thesensor is located downstream of a chopper drum.
 14. The assemblyaccording to claim 1 wherein the harvesting machine is a forageharvester.